1. Scan your graph and save it in a supported image format (e.g. gif, tiff, png, bmp...), or copy it into the clipboard.

  2. Load the graph into DigitizeIt:  File->Open or paste a graph via the clipboard ( Edit->Paste Graph ). You can also take a screenshot ( Edit->Capture Screenshot ).
    Tip: scan your graph at a reasonable resolution, 1000 x 1000 pixels is usually enough

  3. Zoom the graph to your liking with  View->Zoom in

  4. Put the axes:
    a) select Axis->X min
    b) now click on the lower value of the x-axis
    c) enter corresponding x-axis value
    repeat this for X max, Y min, Y max

  5. Select linear, logarithmic or reciprocal scaling:  Axis->x Scale->logarithmic . The x-axis can also be set to Date,Time type.

  6. Now you are ready to go, after  Data->Take points start selecting points by clicking on the screen.
    You can also let DigitizeIt automatically digitize line or scatter plots for you. Select  Auto->Find Line or  Auto->Find Symbol and click on the desired line or one of the symbols, see also line digitizing and symbol digitizing.

  7. Choose, if you want the data sorted  Data Set->Sort

  8. The rest should be self-explanatory, when you are done export the datasets to a file File->Export or copy the data to the clipboard ( Edit->Copy to Clipboard ). Now the data can be pasted or loaded in many other applications.

  9. You can save the complete workspace for later use with File->Save Project.

Open a graph or project

Select  File->Open . By default all supported files will be shown. Select the desired graph or DigitizeIt project and load it.

Supported file types are:

DIG DigitizeIt project files
GIF CompuServe-Bitmap
PNG Portable Network Graphic
BMP Windows or OS/2 Bitmap

Paste a graph from the clipboard

You can import graphs by pasting it from the clipboard ( Edit->Paste Graph ) . This can be used to import graphs in formats, that are not supported by DigitizeIt e.g. pdf-documents. Just open the graph with any image editing application, copy it to the clipboard and paste it into DigitizeIt.

Tip: The fastest way to import graphs in unsupported formats is by using DigitizeIt's capture screenshot feature.

Capture a Screenshot

DigitizeIt can take a screenshot of your desktop ( Edit->Capture Screenshot ) . This can be used to import graphs in formats, that are not supported by DigitizeIt e.g. pdf-documents. Just open the graph with any image editing application and resize the graph to fill most of the screen. Now open DigitizeIt and select Edit->Capture Screenshot . DigitizeIt will hide its own window before the screenshot is taken, so that the result is an image of your desktop without the DigitizeIt window.

Tip: A second way to make a screenshot of your Windows desktop is pressing the "Print" button on your keyboard. This copies the screenshot into the windows clipboard. Now you can paste it into DigitizeIt via Edit->Paste Graph .

Save a project

Select  File->Save Project , enter a filename and click save. This saves the graph with all data sets into a file that can later be loaded into DigitizeIt again.

Set the axes system

1) Select  Axis->X min , now click on the minimum value on the x-axis. Enter the corresponding x value in the dialog box. Numbers can be entered in many formats including scientific notation (e.g. 1.23E5). Repeat this with X max, Y min and Y max.

2) Choose the axis type under  Axis->Scale and select linear, logarithmic or reciprocal scaling. For the x-axis it is also possible to choose Date and Time as axis type. This allows to enter X min and X max in date and time format. In this case the scaling of the x-axis is linear.

It is possible to change the axes itself as well as the scaling between log and linear at all time, already selected data points will be saved correctly. Axes can be in arbitrary angles to each other. There is no need to rotate a graph into exactly horizontal position.

Add data points

Click on Data->Take points . Now select data points on the graph. They are added to the current dataset.

Delete data points

Click on Data->Delete . Now select data points on the graph. They are deleted from the current dataset. Data->Delete all deletes all data points in the dataset.

Handle data sets

A data set is a collection of data points on a graph. All data sets share the same axes system settings. The current data set is always displayed in the toolbar. To add a new data set select Data Set->New , to delete the current data set select Data Set->Delete .
You can also change the data set name to something more descriptive with Data Set->Rename .

Export a dataset

Make the data set you want to export the current data set by selecting the data set with the data set control in the toolbar. Go to  File->Export to export this data set to a file. You can also copy the current current data set to the clipboard with  Edit->Copy to Clipboard and paste it into another application.

Data sets are exported in scientific format with 13 digits of precision. Data can be exported in CSV (.csv) or Excel (.xlsx) format. If you export to CSV (csv=comma separated values), values are separated by commas or semicolons. CSV-Files can also be opened with e.g. Microsoft Excel directly.

Automatic digitizing of line-plots

DigitizeIt can automatically digitize line-plots. Results may vary depending on the quality and colors of your graph.
DigitizeIt can automatically recognize solid lines and and most dashed lines. Dotted lines must be manually digitized.

To automatically digitize a line-plot, select  Auto->Find Line . Now click on the line that you want to digitize. Digitized points are inserted into a new dataset. Holding CTRL (or CMD on the Mac) while clicking on the line will append the new points to the current dataset.
The line will be digitized with maximum resolution, this means one data point for every graph pixel. The line thickness is averaged so the data points are always in the middle of the line. If you want less data points per line, change the distance between digitized points in the Auto Options dialog. If you have defined a search region the line will only be detected within the search region.

Possible problems:

1) Only a part of the line is found.
This may be due to an interrupted line, or pixels with slightly different colors. Try to adjust the color settings in the Auto Options dialog.

2) Crossing lines or intersection with graph axes and grid lines with the same color
DigitizeIt tries to ignore grid lines and crossings and find the next line segment after the crossing.
If lines have different colors and the problem still occurs, try more stringent color settings in the Auto Options dialog. Otherwise you may want to define a search region and digitize the line in parts.

You can adjust the color and max. points on line settings in the Auto Options dialog.

Automatic digitizing of scatter-plots

DigitizeIt can automatically digitize scatter-plots. Results may vary depending on the quality and colors of your graph.

To automatically digitize a scatter-plot, select  Auto->Find Symbols . Now click on one of the symbols, that you want to digitize. It is important to click on a part of the symbol, that has a color different from the background color of your graph, e.g. if you want to digitize circles with a black border but filled with the background color, click on the black border. The size and center of the symbol are then detected automatically and DigitizeIt will find all similar symbols within the entire graph and put them into a new data set.
Please check that the outline of the symbol that you clicked onto is surrounded by a red line. This is the part of the symbol that DigitizeIt considers to be the reference symbol. If the green line does not replicate the outline of the symbol and is too narrow or too wide, please adjust the color settings in the Auto Options dialog.
If you have defined a search region, only symbols within the search region are detected.

If DigitizeIt did not find all of the symbols or too many, you need to adjust the color and similarity settings in the Auto Options dialog.

Define a search region

If you want to restrict automatic digitizing to a specified region of the graph, choose Auto->Search Region . Drag a rectangle with the mouse on the graph. Now lines and symbols are digitized only within this region. You can clear the search region with Auto->Clear Region .

Automatic digitizing options

Here you can adjust settings that apply for automatic digitizing of lines and symbols. Open the dialog with Auto->Options .

1) Max. color difference
DigitizeIt decides if a certain pixel of the graph belongs to a line or a symbol based on the comparison of colors. The pixel you clicked onto, in order to start the digitizing process, sets the reference color.
The color comparison is performed in Lab color space. The color difference value that you can set here is used as the maximum distance between the reference color and the color of a pixel that is considered to belong to a line or symbol.

So, a value of 0 means colors must match exactly, 255 means every color matches (not useful!).

This setting applies to both line and symbol digitizing.

2) Symbol matching in %
This value determines how well a symbol must match the symbol, that you want to digitize, to be considered the same. It sets the number of pixels, that can be different in % of the number of total pixels of the symbol. (If two pixels are the same is determined by the max. color difference setting.)

A value of 0 requires symbols to match exactly, 50 means 50 % of the pixel symbols may be different.

If the symbol detector does not find all of your symbols choose a higher value here, if it finds too many symbols choose a lower value.

3) Distance between points on line in image pixels
This value sets the distance in image pixels between 2 digitized points on the digitized line. Use this setting to reduce the number of points per line.